Not as Easy as It Looks

The term “integrated systems” has appeared to some of us in the field to represent secret meaning for saving money by combining systems. Of course, saving money both for the owner and the contractor is not, in itself, a bad thing, but the part of integrated systems that saves money can go south fast if you have not made yourself ready for the challenges of the future.

By definition, systems integration brings together component subsystems into one system and ensures the subsystems function together as one. Most systems share common characteristics, including the following:

• A structure, defined by components/elements and their composition• A certain behavior, which involves inputs, processing and outputs of material, energy, information or data• Functional and structural relationships to each other, which often are referred to as interconnectivity• Some functions or groups of functions

As you may already know, owners, designers and installers have chosen to integrate or combine more systems to foster efficiencies of operation and lower costs. Some combined or integrated systems consist of aspects or parts that work well together, such as an integrated communications system. An example in the fire alarm industry is an integrated in-building fire emergency voice/alarm communications system.

But as the trend continues, many designers have begun to combine subsystems that are not similar and bring together processes or functions that normally function separately. Here is where one of the challenges comes in. Who has designed the interface of these two systems? If two different companies manufacture these systems, who will take responsibility to ensure they combine properly? Will the manufacturers stand behind the interface design to guarantee the different systems function together as a single system? Or, will you have to assume the responsibility for the interface design and the connections? Assuming the systems combine efficiently and operate as one system, who will test and maintain the interfaced systems?

Obviously, you will need to carefully consider these questions and ask the designer, the manufacturer, the owner and, if the system is a fire alarm system, the authority having jurisdiction (AHJ).

NFPA 72 2010, the National Fire Alarm and Signaling Code, requires that testing personnel have experience in the arrangement and operation of interface equipment and emergency control functions. NFPA 72 2010 also requires that all testing be performed as outlined in accordance with the test methods described in Table 14.4.2.2.

For interfaced equipment, the contractor must test connections by operating or simulating the operation of the supervised equipment. Signals generated by the interfaced equipment (that are required to be transmitted) must be verified at the control unit. And the test frequency for interfaced equipment must be the same as the frequency required by the applicable NFPA standard(s) for the supervised equipment.

You must determine if you have sufficient knowledge in the operation of the interfaced equipment and if you will be responsibile for its correct operation.

The code also defines the requirements for emergency control functions, such as fan control, smoke damper operation, elevator recall, elevator power shutdown, door holder release, shutter release, door unlocking, etc. The code requires you to test this equipment by operating or simulating alarm signals. The testing frequency for emergency control functions remains the same as the frequency required for the initiating device that activates the emergency control function.

Other trades install many of the emergency control functions required to interface with the fire alarm system. In the case of the elevator controls and HVAC controls, you must determine which contractor is responsible for the correct interface with the fire alarm system.

There is much more to interfaced or integrated systems than simply combining and installing them. For example, some of the new requirements in the code for mass notification systems (MNS) allow the building owner to use an existing public address (PA) communications system as an MNS. The PA system must then interface with the fire alarm system. An owner may find it difficult to locate a qualified designer who will step in with a solution to integrate these dissimilar systems that would also meet the requirements of NFPA 72 2010. The AHJ will likely look to you for an acceptable method. The AHJ will want to ensure that, when the MNS must take precedence, it will not interfere with the fire alarm system’s operation under normal conditions. Confirmation of the fire alarm system’s integrity under those conditions will require the AHJ to approve a thorough risk analysis.

These issues are common. What if the building’s telephone system must interface with the MNS? The list goes on.

Be aware of the challenges posed by these myriad interfaced or integrated systems that you will encounter. And, through education and a close working relationship with the designers and manufacturers, you will prepare yourself for these challenges.

MOORE, a licensed fire protection engineer, frequent speaker and an expert in the life safety field, is a past chair of the NFPA 72 Technical Correlating Committee. Moore is a principal with Hughes Associates Inc. at the Warwick, R.I., office. He can be reached at wmoore@haifire.com.